Incoming query today: I am writing to you in search of help in the process of positioning my (novel) in the marketplace, promotion and marketing it.
Before you send a query to an agent, be clear about what an agent does. It's not promotion and marketing. It's not positioning it in the marketplace. It's also not editing, proof reading or a bunch of other stuff.
My job is to sell your book to a publisher. Other parts of the publication process may happen including promotion and marketing, editing, and proofing, but those aren't why you query an agent.
If you expect your agent to be your publicist and marketing expert you're in for a really unhappy surprise.
Please don't let your desire to sound businesslike make you look uninformed. Just tell me about the book you wrote.